From: Kuniyuki Iwashima <kuniyu@amazon•com>
To: "David S. Miller" <davem@davemloft•net>,
Eric Dumazet <edumazet@google•com>,
Jakub Kicinski <kuba@kernel•org>, Paolo Abeni <pabeni@redhat•com>,
David Ahern <dsahern@kernel•org>
Cc: Kuniyuki Iwashima <kuniyu@amazon•com>,
Kuniyuki Iwashima <kuni1840@gmail•com>, <netdev@vger•kernel.org>,
kernel test robot <lkp@intel•com>
Subject: [PATCH v1 net-next 01/12] rtnetlink: Make per-netns RTNL dereference helpers to macro.
Date: Mon, 21 Oct 2024 11:32:28 -0700 [thread overview]
Message-ID: <20241021183239.79741-2-kuniyu@amazon.com> (raw)
In-Reply-To: <20241021183239.79741-1-kuniyu@amazon.com>
When CONFIG_DEBUG_NET_SMALL_RTNL is off, rtnl_net_dereference() is the
static inline wrapper of rtnl_dereference() returning a plain (void *)
pointer to make sure net is always evaluated as requested in [0].
But, it makes sparse complain [1] when the pointer has __rcu annotation:
net/ipv4/devinet.c:674:47: sparse: warning: incorrect type in argument 2 (different address spaces)
net/ipv4/devinet.c:674:47: sparse: expected void *p
net/ipv4/devinet.c:674:47: sparse: got struct in_ifaddr [noderef] __rcu *
Also, if we evaluate net as (void *) in a macro, then the compiler
in turn fails to build due to -Werror=unused-value.
#define rtnl_net_dereference(net, p) \
({ \
(void *)net; \
rtnl_dereference(p); \
})
net/ipv4/devinet.c: In function ‘inet_rtm_deladdr’:
./include/linux/rtnetlink.h:154:17: error: statement with no effect [-Werror=unused-value]
154 | (void *)net; \
net/ipv4/devinet.c:674:21: note: in expansion of macro ‘rtnl_net_dereference’
674 | (ifa = rtnl_net_dereference(net, *ifap)) != NULL;
| ^~~~~~~~~~~~~~~~~~~~
Let's go back to the original simplest macro.
Note that checkpatch complains about this approach, but it's one-shot and
less noisy than the other two.
WARNING: Argument 'net' is not used in function-like macro
#76: FILE: include/linux/rtnetlink.h:142:
+#define rtnl_net_dereference(net, p) \
+ rtnl_dereference(p)
Fixes: 844e5e7e656d ("rtnetlink: Add assertion helpers for per-netns RTNL.")
Link: https://lore.kernel.org/netdev/20241004132145.7fd208e9@kernel.org/ [0]
Reported-by: kernel test robot <lkp@intel•com>
Closes: https://lore.kernel.org/oe-kbuild-all/202410200325.SaEJmyZS-lkp@intel.com/ [1]
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon•com>
---
include/linux/rtnetlink.h | 21 ++++++---------------
1 file changed, 6 insertions(+), 15 deletions(-)
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 8468a4ce8510..0e62918de63b 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -137,21 +137,12 @@ static inline void ASSERT_RTNL_NET(struct net *net)
ASSERT_RTNL();
}
-static inline void *rcu_dereference_rtnl_net(struct net *net, void *p)
-{
- return rcu_dereference_rtnl(p);
-}
-
-static inline void *rtnl_net_dereference(struct net *net, void *p)
-{
- return rtnl_dereference(p);
-}
-
-static inline void *rcu_replace_pointer_rtnl_net(struct net *net,
- void *rp, void *p)
-{
- return rcu_replace_pointer_rtnl(rp, p);
-}
+#define rcu_dereference_rtnl_net(net, p) \
+ rcu_dereference_rtnl(p)
+#define rtnl_net_dereference(net, p) \
+ rtnl_dereference(p)
+#define rcu_replace_pointer_rtnl_net(net, rp, p) \
+ rcu_replace_pointer_rtnl(rp, p)
#endif
static inline struct netdev_queue *dev_ingress_queue(struct net_device *dev)
--
2.39.5 (Apple Git-154)
next prev parent reply other threads:[~2024-10-21 18:33 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-21 18:32 [PATCH v1 net-next 00/12] ipv4: Convert RTM_{NEW,DEL}ADDR and more to per-netns RTNL Kuniyuki Iwashima
2024-10-21 18:32 ` Kuniyuki Iwashima [this message]
2024-10-23 18:58 ` [PATCH v1 net-next 01/12] rtnetlink: Make per-netns RTNL dereference helpers to macro Simon Horman
2024-10-21 18:32 ` [PATCH v1 net-next 02/12] rtnetlink: Define RTNL_FLAG_DOIT_PERNET for per-netns RTNL doit() Kuniyuki Iwashima
2024-10-21 18:32 ` [PATCH v1 net-next 03/12] ipv4: Factorise RTM_NEWADDR validation to inet_validate_rtm() Kuniyuki Iwashima
2024-10-21 18:32 ` [PATCH v1 net-next 04/12] ipv4: Don't allocate ifa for 0.0.0.0 in inet_rtm_newaddr() Kuniyuki Iwashima
2024-10-21 18:32 ` [PATCH v1 net-next 05/12] ipv4: Convert RTM_NEWADDR to per-netns RTNL Kuniyuki Iwashima
2024-10-21 18:32 ` [PATCH v1 net-next 06/12] ipv4: Use per-netns RTNL helpers in inet_rtm_newaddr() Kuniyuki Iwashima
2024-10-21 18:32 ` [PATCH v1 net-next 07/12] ipv4: Convert RTM_DELADDR to per-netns RTNL Kuniyuki Iwashima
2024-10-21 18:32 ` [PATCH v1 net-next 08/12] ipv4: Convert check_lifetime() " Kuniyuki Iwashima
2024-10-21 18:32 ` [PATCH v1 net-next 09/12] rtnetlink: Define rtnl_net_trylock() Kuniyuki Iwashima
2024-10-21 18:32 ` [PATCH v1 net-next 10/12] ipv4: Convert devinet_sysctl_forward() to per-netns RTNL Kuniyuki Iwashima
2024-10-21 18:32 ` [PATCH v1 net-next 11/12] ipv4: Convert devinet_ioctl() to per-netns RTNL except for SIOCSIFFLAGS Kuniyuki Iwashima
2024-10-21 18:32 ` [PATCH v1 net-next 12/12] ipv4: Convert devinet_ioctl to per-netns RTNL Kuniyuki Iwashima
2024-10-29 11:20 ` [PATCH v1 net-next 00/12] ipv4: Convert RTM_{NEW,DEL}ADDR and more " patchwork-bot+netdevbpf
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